Update app.py

app.py

@@ -4,7 +4,7 @@ import uuid
 import langchain
 from langchain_google_genai import GoogleGenerativeAI
 from langchain_core.prompts import ChatPromptTemplate,MessagesPlaceholder
-from langchain_core.output_parser import StrOutputParser
+from langchain_core.output_parsers import StrOutputParser
 from langchain_community.chat_message_histories import SQLChatMessageHistory
 from langchain_core.runnables.history import RunnablesWithMessageHistory